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Letters Patent No. 79,000, dated June 16, 1868.

`IMPROVEMlhlT IN DEVICE FOR FITTING WRIST-PINS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that VI, GEORGE RAFT, of'Erie, in the county of Erie, and State of Pennsylvania, have invented a new and improved Lathe-Attachment for Fitting Wrist-Pins in Cranks; and I do hereby declare that the following is a ful1clear, and exact description thereof, which will enable others skilled in the nrt to make and use the same, reference being had to the accompanying drawings, forming part of this specification 'Figure I is a top view of my invention.

Figure 2 is a side view of the same.

Similar letters of reference indicate corresponding parts. y

The object of this invention is to accomplish the iitting of wrist-pins in cranks or crank-disks, whereby the axis of the wrist-pin shall be exactly 'parallel with the axis of the crank-shaft, a lcondition always requisite to obtain a smoothly-working crank-shaft.

It consists of a boring-attachment, which is borne 'by the lathe-`carriage, to bore outvthe eye for the wristpin, While the crank-shaft`is still on the centres ot' the lathe.`

The boring-attachment consists of the tool-shaft A, bearing a cog-wheel, B, the said shaft having a long bearing in the frame-plate C of the machine.

This bearing is bored out of the frame-plate, whichlatter is cast with s-uiicient thickness of' metal at that point for the purpose, as shown at D. The bearing is provided with liibricating-holes a a.

The counter-shaft E has its bearings in the extensions G Gr, forming'part of the frame-plate C, or a single long bearing, like that of `the shaft A, may be formed in the plate C.

The shaft E bears a pinion, H, which engages with the cogfwheel B, and the same shaft also bears a pulley, I, by means of which a belt from a pulley on the counter-'shaft of the lathe transmits motion to theboringattachment.

A rib, b, is cast on the plate C, for the purpose of fitting in-the slot of the tool-post, which latter forms partof the carriage of aV lathe, and this rib being made accurately parallel with the tool-shaft A, the latter will bore a hole in the crankwhieh will be accurately parallel with the axis of the crankfshaft, providingthat the tool-rest be adjusted exactly'at right angles to the ldngitudinal feed of the lathe, which adjustment,-when once made correctly, will remain so, with reasonable care.l A. collar, d, Von the shaft'E, servesY to keep' the latter in place. c is the slot for the boring-tool or cutter, and e e'are holes through the plate C and its rib b, which serve, in connection with any suitable bolts andV nuts, to ax the attachment firmly to the tool-post.

At fig. 2 the machine is shown bolted to the tool-post .I by bolt fand'nut g. h isa-nut AonV the shaft A, and serves to hold the wheel B in place. i i

The manner of using my invention is as follows:V The crank or crank-disk is first bored out to it on the shaft, heated and shrunk on the latter,fand also vfirmly keyed thereon. The shaft is then centred and'put intothe lathe, and the last-chip taken off from the same. The crank or crank-disk is thenA 'forced Vup and brought down upon the lathe iu front, and secured firmly in such a position that the boring-attachment can be adjusted to bore the eye in the proper place, by setting out thetool-post with the cross-feed, and raising or lowering the same, to complete the adjustment. y Y i The longitudinal feed is then set in motion, and the boring-attachment also set in motion, whereby the hole or eye'is bored in the crank, and the axis of the hole so bored must be accurately parallel to the axis of the crank-shaft, if the tool-rest be correctly fitted to the carriage, which is generally the case.

I claim as new, and desire to secure by Letters Iatent-V The improved device herein described for boring out the eyes for wrist-pins.

GEORGE nerr.

llVitnesses:v

E. Gmnwsna, JAMES E. Tnonrn, H. M. REED. 

